Segment and Geographic Information , Net Sales by Reportable Segment (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Apr. 26, 2019	Jan. 25, 2019	Oct. 26, 2018	Jul. 27, 2018	Apr. 27, 2018	Jan. 26, 2018	Oct. 27, 2017	Jul. 28, 2017	Apr. 26, 2019	Apr. 27, 2018	Apr. 28, 2017
Segment Reporting Information [Line Items]
Total	$ 8,146	$ 7,546	$ 7,481	$ 7,384	$ 8,144	$ 7,369	$ 7,050	$ 7,390	$ 30,557	$ 29,953	$ 29,710
Cardiac and Vascular Group
Segment Reporting Information [Line Items]
Total									11,505	11,354	10,498
Minimally Invasive Therapies Group
Segment Reporting Information [Line Items]
Total									8,478	8,716	9,919
Restorative Therapies Group
Segment Reporting Information [Line Items]
Total									8,183	7,743	7,366
Diabetes Group
Segment Reporting Information [Line Items]
Total									$ 2,391	$ 2,140	$ 1,927